A top tier opponent like Crenshaw could take him down in the primary for sure. He's clearly a long term liability and an underperformer vs. generic R. This latest misstep may not matter by itself, but it's one of many.
I can't think of any other guy who has such a national profile yet is despised by nearly everyone, even his own party
He very well may be despised by Republicans on the Hill, but I don't think it really has been sufficiently demonstrated that he is particularly unpopular among rank-and-file Republican voters, despite that being such a prominent narrative. If my recollection serves, his approval ratings were never particularly poor in recent years, and I believe they often eclipsed Cornyn's.
In 2016, Trump won 4.7 million votes and Hillary won 3.9 million in Texas. Around 8.6 million voted.
In 2018, Cruz won 4.3 million and Beto won 4 million. Around 8.3 million voted
In 2018, Abbott won 4.7 million and 3.5 million. Around 8.2 million voted
That is about 400k voters who voted for both Beto and Abbott
If we assume that the general electorate for 2018 in Texas was roughly the same as 2016
That is 400k Republicans who voted for Beto because they hated Cruz (or loved Beto)
I can't think of any other red state where it was so clear. Sure, Beto was an amazing canidate but there was a lot of love lost for Cruz. If this state was Ohio or Florida, the GOP would have lost with so many cross overs
Basically, Cruz has some haters in the state GOP compared to Abbott and Cornyn
